You’re ready to tackle the overgrown grass, but instead of a satisfying roar, your lawn mower coughs, sputters, and starts spitting out oil. This isn’t just a messy inconvenience – it’s a sign something’s wrong. This article will explore the common culprits behind lawn mower oil spitting, from simple fixes to more complex issues. We’ll guide you through identifying the problem, understanding potential causes, and tackling solutions, leaving you with a better understanding of your lawn mower’s health and how to keep it running smoothly.
A Quick Overview:
Lawn mower oil spitting can be caused by a variety of factors, including overfilling the crankcase, a faulty carburetor, clogged air filters, damaged piston rings, or even a worn-out engine. The key to solving this problem lies in identifying the specific cause through careful observation and inspection.
Overfilling the Crankcase
The most common reason your lawn mower might be spitting oil is simple: you’ve overfilled the crankcase. Lawn mower engines have a specific oil capacity, and exceeding that limit can lead to the oil being forced out through the breather tube or other openings.
Checking Oil Levels
- Locate the dipstick: It’s usually a metal rod with a handle, located near the engine.
- Remove the dipstick: Wipe it clean with a cloth.
- Reinsert the dipstick fully: Remove it again and check the oil level.
The oil should be at the “Full” mark or slightly below. If it’s above the “Full” mark, you’ll need to drain some oil.
Draining Excess Oil
- Locate the drain plug: It’s usually a bolt or screw on the bottom of the crankcase.
- Place a drain pan: Under the drain plug to catch the oil.
- Loosen the drain plug: Allow the oil to drain completely.
- Tighten the drain plug: Once the oil has drained, tighten the drain plug.
- Add the correct amount of oil: Refer to your lawn mower’s manual for the recommended oil type and capacity.
Carb Issues: A Common Culprit
A faulty carburetor can be a major contributor to oil spitting. The carburetor’s job is to mix air and fuel, and if it’s not working correctly, the fuel-air mixture can become too rich, causing unburned fuel to condense and mix with oil in the crankcase. This mixture can then be pushed out through the breather tube, leading to oil spitting.
Signs of a Faulty Carburetor
- Difficult starting: The engine may struggle to start or run smoothly.
- Black smoke: Excessive black smoke coming from the exhaust indicates a rich fuel mixture.
- Fuel smell: A strong fuel odor around the engine is another sign of a carburetor problem.
Cleaning the Carburetor
- Locate the carburetor: It’s usually attached to the engine near the air filter.
- Remove the carburetor: Refer to your lawn mower’s manual for specific instructions.
- Disassemble the carburetor: Carefully take it apart to access the internal parts.
- Clean the parts: Use a carburetor cleaning kit or compressed air to remove dirt and debris.
- Reassemble the carburetor: Carefully put it back together.
- Reinstall the carburetor: Make sure it’s properly connected.
Clogged Air Filter: An Often Overlooked Problem
A clogged air filter restricts airflow to the engine, leading to a rich fuel mixture. This can cause unburned fuel to build up in the crankcase, resulting in oil spitting.
Identifying a Clogged Air Filter
- Visual inspection: Look for dirt and debris on the air filter.
- Check for restrictions: Gently try to blow air through the filter. If there’s significant resistance, it’s clogged.
Replacing or Cleaning the Air Filter
- Replaceable filters: If your air filter is disposable, simply replace it with a new one.
- Washable filters: If your air filter is washable, follow the manufacturer’s instructions to clean it.
Engine Problems: More Serious Causes
While overfilling and carburetor issues are common, oil spitting could also signal more serious engine problems:
Worn-out Piston Rings
Piston rings create a seal between the piston and the cylinder wall, preventing oil from entering the combustion chamber. If the piston rings are worn out, oil can seep past them and end up in the combustion chamber, leading to oil spitting and smoke.
Damaged Cylinder Walls
Scratches or other damage to the cylinder walls can also compromise the seal between the piston and the cylinder, allowing oil to enter the combustion chamber.
Signs of Engine Problems
- Blue smoke: Blue smoke from the exhaust is a telltale sign of oil burning in the combustion chamber.
- Loss of power: The engine may lose power or run rough.
- Oil consumption: You may notice a decrease in oil level, even after checking and adding oil.
If you suspect engine problems, it’s best to consult a qualified mechanic for diagnosis and repair.
Taking Preventive Measures
To minimize the risk of oil spitting, it’s essential to practice good maintenance habits:
- Regular oil changes: Change the oil according to the manufacturer’s recommendations.
- Use the correct oil: Use the oil type and viscosity specified in your lawn mower’s manual.
- Check oil levels: Before each use, check the oil level and top it off if necessary.
- Clean the air filter: Inspect and clean the air filter regularly.
- Inspect the carburetor: Inspect the carburetor for signs of dirt or debris.
Conclusion: Get Your Lawn Mower Running Smoothly Again
Oil spitting from your lawn mower can be frustrating, but it doesn’t have to be a major headache. By understanding the common causes and taking the necessary steps, you can often identify and solve the problem yourself. However, if you suspect engine problems, it’s always best to seek professional help. Regular maintenance is key to keeping your lawn mower running smoothly and preventing future issues.
FAQs
Here are 7 frequently asked questions with answers regarding lawn mower oil spitting:
1. What does it mean when my lawnmower is spitting oil?
When your lawnmower is spitting oil, it means that oil is being expelled from the engine’s crankcase, often through the exhaust or the carburetor. This is not a normal occurrence and indicates a problem with your mower’s engine. It can be caused by a number of factors, including overfilling the crankcase, a damaged piston ring, or a faulty valve.
Ignoring the issue can lead to further damage and costly repairs. It’s crucial to diagnose the problem and take appropriate steps to fix it before using your lawnmower again.
2. Is it safe to keep using my lawnmower if it’s spitting oil?
No, it is not safe to keep using your lawnmower if it’s spitting oil. This is because the oil can damage the engine’s internal components, leading to a breakdown or even a fire. Additionally, the oil expelled can create a hazardous slippery surface, potentially causing you to lose control of the mower.
It’s crucial to stop using your lawnmower immediately and address the problem before using it again. Doing so could result in serious damage to your lawnmower and could pose a safety hazard.
3. What could be the reasons for my lawnmower spitting oil?
Several reasons can cause a lawnmower to spit oil. These include:
- Overfilling the crankcase: Adding too much oil can cause it to be forced out through the engine’s breather system.
- Damaged piston rings: Worn or damaged piston rings can allow oil to seep into the combustion chamber and be expelled through the exhaust.
- Faulty valves: Leaky valves can allow oil to escape into the combustion chamber and be burned, resulting in oil spitting.
- Clogged breather system: A blocked breather system can cause a buildup of pressure in the crankcase, leading to oil expulsion.
- High engine temperature: Extreme engine temperatures can cause oil to thin and vaporize, leading to oil spitting.
4. How can I diagnose the cause of my lawnmower spitting oil?
Diagnosing the cause of oil spitting can be tricky, but here’s a guide to help you:
- Check the oil level: Ensure it’s within the correct range as indicated on the dipstick. If overfilled, drain the excess oil.
- Inspect the exhaust: If oil is present in the exhaust, it suggests a problem with the piston rings or valves.
- Check the breather system: Make sure it’s not clogged.
- Check the engine temperature: If the engine is overheating, it might be the culprit.
- Consider a mechanic’s expertise: If unsure, consult a lawnmower mechanic for a professional diagnosis.
5. How can I prevent my lawnmower from spitting oil?
Preventing your lawnmower from spitting oil is crucial for maintaining its health and longevity. Here’s how:
- Maintain the correct oil level: Use the appropriate type and amount of oil, checking the dipstick regularly.
- Replace worn parts: Replace the piston rings and valves when necessary.
- Clean the breather system: Clean or replace it as needed.
- Regularly check the engine temperature: Prevent overheating by ensuring proper cooling system function.
- Use high-quality oil: Use the recommended type and viscosity of oil to prevent premature wear.
6. How do I fix a lawnmower that is spitting oil?
Fixing a lawnmower that is spitting oil requires addressing the specific cause. Here’s a general approach:
- If overfilled: Drain the excess oil.
- If piston rings or valves are damaged: Replace the damaged parts.
- If the breather system is clogged: Clean or replace it.
- If engine temperature is high: Address any cooling system problems.
If unsure about the cause or repair, consult a qualified lawnmower mechanic.
7. Can I continue using my lawnmower after fixing the oil spitting problem?
After successfully fixing the oil spitting problem, it’s generally safe to use your lawnmower again. However, it’s advisable to carefully monitor it for any recurring issues.
Keep an eye on the oil level, listen for unusual noises, and check for oil leaks. If you notice any of these, stop using your lawnmower immediately and seek professional assistance. Regular maintenance and inspections will help ensure your lawnmower continues to operate safely and efficiently.